Re: People’s willingness to accept overdetection in cancer screening: population survey
Goodman raises the interesting question of selection of most suitable citation to support a statement in a published paper, in this case whether an earlier, rather than a later study should be cited.  If evidence from a systematic review had been available, this would have provided the best solution.
A similar query arises in connection with a paper discussing the harms associated with unnecessary testing and treatment in connection with overdetection.  The authors properly cite four systematic reviews (5, 6, 8 and 9 in extract below) and one paper reporting the results of a trial of radiotherapy (7 in extract below) to illustrate this, as follows:
“Overdetection in breast cancer screening results in more breast surgery including mastectomy and deaths from cardiovascular disease and secondary cancers after radiotherapy. In screening for prostate cancer, harms from overdetection include urinary incontinence and erectile dysfunction after prostatectomy and bowel dysfunction after radiotherapy. Screening for bowel cancer is associated with the risks of further testing with colonoscopy and the associated complications of this procedure (bleeding and perforation).”
However, another publication in June 2014 describes current knowledge of the cardiotoxicity arising from cancer treatments.  It also outlines gaps in knowledge and indicates directions for future research and guideline development, as discussed during the 2014 Cancer Survivorship Summit organised by the European Organisation for Research and Treatment of Cancer (EORTC).
An extract from this paper  draws attention to the change over time with respect to increased mortality and morbidity from the use of different radiotherapy techniques:
“Increased mortality and morbidity from heart disease has also been reported after radiotherapy for breast cancer (BC), especially after some of the radiotherapy techniques that were used in the past (19) and (20). Studies on cardiovascular toxicity following radiation for BC [breast cancer] frequently compare patients with left-sided and right-sided BC or compare BC patients with the general population …”
Would it not have been preferable for Van den Bruel et al to cite the paper by Aleman et al, which provides a broad overview of cardiovascular toxicity?
 Goodman NW. Earlier, not later, studies should be cited in support of statements. BMJ rapid response 4th March 2015
 Van den Bruel, AV, Jones C, Yang Y, Oke J, Hewitson P. People`s willingness to accept overdetection in cancer screening: population survey. BMJ 2015;350:h980
 Aleman BMP, Moser EC, Nuver J, Suter TM, Maraldo MV, Specht L, Vrieling C, Darby AC. Cardiovascular disease after cancer therapy. European Journal of Cancer Supplements, Vol.12, Issue 1, June 2014, 18-18 doi:10.1016/j.ejcsup.2014.03.002
Competing interests: No competing interests